More than eight years in the making, the development firm is testing it’s self-driving technology on Arizona public roads—without anyone in the driver’s seat.

“We prepared for this next phase by putting our vehicles through the world’s longest and toughest ongoing driving test,” the Waymo team wrote in a blog post.

The Google spin-off has driven more than 3.5 million autonomous miles across 20 U.S. cities, and practiced some 20,000 “rare and unusual cases” at its private track.

“We’re building our vehicles to be the most experienced driver on the road,” the company said, boasting safety features like backup steering, braking, computer, and power.

For the last year, Waymo has offered free taxi rides to folks near Chandler, Ariz., shuttling people like Candace, Ted, and their four kids to work, school, soccer practice, and choir rehearsal in its fleet of autonomous vehicles.

The modified Chrysler Pacifica minivans, however, always had a human employee behind the wheel, ready to take over in case of emergency. Until now.

Confident in its technology, the enterprise has ditched its safety driver, and invites brave travelers in the Phoenix area to enjoy a quiet ride, free of inevitable cabbie small talk.

Initially, passengers will have to contend with an employee observing from the back, there to press the “pull over” button if the car malfunctions, Ars Technica reported.

Eventually, Waymo will expand its commercial driverless taxi service to more people and places. The idea is that a fleet of vehicles—rather than a personal ownership model—will allow more passengers to experience autonomous technology, sooner.

“With Waymo in the driver’s seat, we can reimagine many different types of transportation, from ride-hailing and logistics, to public transport and personal vehicles, too,” the blog announcement said. “We’ve been exploring each of these areas, with a focus on shared mobility.”

Parent company Google in 2015 successfully completed its first fully self-driving trip, when one of its prototype vehicles chauffeured Steve Mahan, who is legally blind, through Austin.

“When fully self-driving vehicles become part of people’s everyday routine, we can move closer to our goal of making transportation safe and easy for everyone,” Waymo said.